We are now running ink that is 12-14 months out of date, with no problem at all.
Having the date of the machine set at 2006 has caused no problems what so ever
I would not recommend running with chips that don't tell you when ink is used up, as it is a hassle to have to remove and weigh cartridges before big jobs. Of course if you use a system where you can see how much ink you have, it's different.
To compare milk to ink is just plain ridiculous. It is not "fresh". Yes, it will maybe eventually go bad, but it's closer to compare to motor oil or car paint, which is fine almost forever as long as it is not opened.
And, removing the battery can't hurt, how can you even suggest that? Does anyone really think that a manufacturer would make a piece of equipment that you cannot replave parts in? What if the battery goes bad? Replace the whole printer? Think not.
I do agree with the warranty part though, don't let a tech see out of date ink if you are trying to have something covered under warranty...